The most basic function of a website is to present information in a hierarchical structure called the Outline. The Document Outline is created using the heading elements h1, h2, h3, h4, h5, and h6.
Heading elements have a rank given by the number in their name. The h1 element has the highest rank, the h6 element has the lowest rank, and two elements with the same name have equal rank.
Use the rank of heading elements to create the document outline.